Portable and adjustable knockdown scaffold



Nov. 23, 1943. 4 c. c. DROEGER 2,335,046

I PORTABLE AND ADJUSTABLE KNOCK-DOWN SCAFFOLD Filed Aug. 3, 1942 2 Sheets-Sheet 1 Nov 23, 1943. c. c. DROEGER PORTABLE AND ADJUSTABLE KNOCK-DOWN SCAFFOLD Filed Aug. 3, 1942 2 Sheets-Sheet 2 Armin/16.

Patented Nov. 23, 1943 UNITED STATES E ATENT FFICE PGRTABLE AND ADJUSTABLE KNOCKDOWN SGAFF OLD 9 Claims.

The present invention relates to a portable adjustable knock-down scaffold which is primarily intended for light applications within doors, such as for use in hanging drapes, decorating walls, attending book shelves and stock shelves, interior painting, electrical work, acoustical application, and the like. The primary object of the invention is to provide a light, readily adjustable, readily assemblable and disassemblable, portable scaffold unit which will take up relatively small space when not in use, and which may be moved from point to point within a building or suite of rooms, passing readily through doorways, aisles, and between or over desks, chairs, stock piles, and the like. Further. objects of the invention will appear as the description proceeds.

For the accomplishment of the above and related objects, my invention may be embodied in the forms illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that change may be made in the specific constructions illustrated and described, so long as the scope of the appended claims is not violated.

Fig. 1 is an isometric view of my scaffold unit assembled for use;

Fig. 2 is an exploded view of the platform frame forming a part thereof;

Fig. 3 is an enlarged View of one form of one corner of the platform frame;

Fig. 4 is a section taken substantially on the plane indicated by the line l4 of Fig. l and looking in the direction of the arrows;

Fig. 5 is a section of a further detail, upon an enlarged scale;

Fig. 6 is an isometric view of a modified form of the detail of Fig. 5; and

Fig. '7 is an isometric fragmental View of a base frame which may, in some instances, be desirably used.

Referring more particularly to Fig. 1, it will be seen that my scaflold unit comprises a pair of end frames indicated generally by the reference numerals ll! and ii. The end frame Ill is made up of the two uprights l2 and it, each of which may preferably be an angle iron, the upright l2 having perpendicularly related flanges l4 and I5 and the upright l3 having similarly related flanges l6 and ll. It will be seen that the flanges l4 and 16 project toward each other in a common plane,while the flanges I5 and H are remote from each other and liein parallel planes perpendicular to. the common plane of the flanges id and it. The flanges l5 and 14 are connected together by cross braces [8, which may preferably be welded to said flanges, said cross members being preferably so spaced as to form convenient ladder rungs. The flange ll of the upright i3 is provided with a series of vertically spaced perforations ill; and the flange 15 of the upright 12 is provided with a similar series of perforations (not shown) respectively aligned with the perforations iii.

In the form of the invention illustrated in Fig. 1, a block it is suitably secured to the base of the upright l2 between the flanges Hi and It thereof, and mounts a caster wheel 2i while a similar block (not shown) is suitably secured between the flanges iii and ii at the base of the upright I3, and mounts a caster wheel 22, so that the end frame it is supported upon the caster wheels 2! and 22.

The end frame it comprises two uprights 23 and 24, each of which is preferably an angle iron; the flanges 25 and 2i of said angle irons projecting toward each other and lying in a common plane parallel to the plane of the flanges I6 and I4, and the flanges 26 and 23 being remote from each other, parallel to each other, and

substantially coplanar with the flanges l5 and 11, respectively. Cross braces 2% correspond in position to the cross braces 18 and are suitably secured to the flanges 25 and 27. The flange 28 is formed with a series of vertically spaced perforations 30, which lie, respectively, in common horizontal planes with the perforations l3, while the flange 23 is formed with a similar series of perforations St. A block 32 is suitably mounted between the flanges 25 and 28 at the base of the upright 23 and supports a caster wheel 33; while a similar block at, similarly mounted at the base of the upright 2 t, mounts a caster wheel 35; so that the end frame ii is supported by the caster wheels 33 and 35.

It will be seen that the end frames lb and II are independent units. They are connected together, in assembling the scaffold, by a platform frame which comprises the rails 36 and i l now to be described.

The rail 36 is of T-section, the stem thereof being indicated by the reference numeral 31. To one end of the cross arm of the T-rail 36 is suitably secured, as by welding, a plate 38 carrying two vertically spaced pins 39 and 4d. Said pins 39 and it? are so spaced, with relation to the spacing of the perforations 19, that they'may be simultaneously projected through any selected pair of said perforations i9, whereby the end of the rail which carries the plate 38 may be secured, in any one of a plurality of positions of vertical adjustment, to the upright |3. To the opposite end of the cross arm of the T 36 is similarly secured a similar plate 4|, similarly carrying pins 42 and 43, selectively projectible through any selected pair of the perforations 30 in the flange 28 of the upright 24 of the end frame ll. It will be seen that, because of the vertical spacing of the pins 39 and 49 and 42 and 43, the projection of said pins through selected perforations of the series l9 and 38 not only supports the rail 36 upon the uprights l3 and 24, but further provides a connection between said uprights and braces said uprights against oscillation in the plane of the cross arm of the T-rail 36. In other words, the projection of said pinsthrough said perforations constitutes means for preventing relative movement between the rail 36 and the uprights |3 and 24, in any direction transaxial to the said pins. Further means later to be described, is provided for preventing relative movement between said rail and said uprights, axially of said pins.

The rail 44 is likewise of T-section, the stem thereof being indicated by the reference numeral 45; and said rail 44 is provided with a plate 46 similar to the plate 38 and provided with pins 41 and 48 and with a plate 49 similar to the plate 4| and carrying pins 50 and 5|. The pins 41 and 48 are similarly enterable in the perforations of the flange l5 of the upright I2, while the pins 50 and 5| are similarly enterable in the perforations 3| of the flange 26 of the upright 23.

Adjacent one end of the stem 31 of the rail 36 is mounted a cross brace 52 which may preferably be an angle iron having perpendicularly ar arranged flanges 53 and 54. Said cross brace 52 is relatively permanently secured to the stem 31 by a rivet 55, the flange 54 thereof being cut away, as at 56, to permit oscillation of said brace 52 about the axis of the rivet 55. Adjacent the opposite end of the cross brace, the flange 54 is cut away as at 51; and a pin 58 is adapted'to pass through an aperture in the last-mentioned end of the cross brace 52 and through a registering aperture 59 in the stem 45 of the'rail 44 to connect said brace 52 with said rail 44. Similarly, a cross brace 60 is pivotally riveted at 6| to the stem 45 of the rail 44 and is apertured at its opposite end to receive a pin 62 passing through a suitable aperture 63 in the stem 3'! of the rail 36. A similar brace 64 is pivoted at 65 to the stem 3'! of the rail 6 and is adapted to be connected to the stem 45 of the rail 44 by a pin 66 passing through aperture 67; while a fourth brace 68 is pivoted at 69 to the rail stem 45 and is adapted to be connected to the rail stem 31 by a pin ill passing through the aperture 1|.

It will be seen that the platform frame 'is thus readily assembled with the end frames I0 and by entering the pins 39, 40, 42, 43, 41, 48, 50, and 5| in selected apertures in the uprights, and thereafter swinging the braces 52, 6B, 64, and 68 into positions such as to permit the engagement of the removable pins 58, 62, 66, and 10 in the apertures 59, 63, 61, and II, respectively. It will further be seen that, after engagement of such pins in said apertures, the platform frame rigidly secures together the upper ends of the end frames wand-II.

In the embodiment of the invention illustrated in Figs. 1, 2, 3, and 5, each of the said pins is formed with a transaxial groove, such grooves in the pins 42 and 43 being indicated by the refer:

ence numerals 89 and 90, respectively. When said pins are passed through the perforations in the uprights, said pins can be forced downwardly so that the grooves snugly receive portions of the peripheral walls of the perforations through which they are entered, in the manner particularly in.- dicated in Fig. 5. This is one means for securing the rails and uprights against relative movement axially of said pins. An alternative means for performing this function is indicated in Fig. 6, in which the pin 42 carried by the plate 4| has been passed through the aperture 30 in the flange 28' of an upright, behind the flange 27' thereof. The pin 42' is formed with an axially elongated, transaxially extending slot 9| in that portion of said pin projected through the perforations 38'; and a Wedge element 92 is driven through said slot 9| to wedge itself between the extremity of said slot 9| and the adjacent wall of the flange 28.

While the above-described structure provides a scaffold unit of sufficient rigidity for ordinary uses, and while that structure has certain advantages, particularly including the capacity for being passed over an obstruction which it must straddle, it may be that, in some instances, it will be considered desirable to increase the rigidity of the structure by connecting together the lower ends of the end frames. Means for accomplishing that purpose is indicated in Fig. 7, in which there is illustrated a base frame indicated generally by the reference numeral 12 and preferably (for purposes of maintaining maximum lightness of integrated units) consisting of two frames 13 and 14 secured together. The frame 13 comprises parallel side bars 15 and 16 and parallel end bars 11 and 18, all preferably being angle irons, and secured together by gusset plates 19 riveted in the corners of said frame. The frame 14 similarly comprises parallel side bars and 8| and parallel end bars 82 and 83 similarly assembled by means of gusset plates 84 riveted to the inwardly projecting horizontal flanges of such angle iron bars. The end bar 18 of the frame 13 and the end bar 82 of the frame 14 are secured together by rivets 85; and the bases of the uprights l2 and I3 of the end frame l8 rest upon gusset plates 19, being secured thereto by rivets or bolts 93, while the bases of the uprights 23 and 24 of the end frame rest upon gusset plates 84, being secured in place by rivets or bolts 94. Caster wheels 86 are suitably mounted at the corners of the frame 12 to support the scaffold unit. 7

The frame 12, or one like it, may readily be used to provide a platform resting upon the T stems 31 and 45 of the rails 36 and 44; and, when so used, said frame is inverted, and slabs of plyboard or other suitable material are secured to the horizontal flanges of the angle irons making up said frame, all in the manner illustrated in Figs. 1 and 4. V v I It will be seen that the scaffold unit disclosed herein is highly adaptable to dimensioning of such character as to permit its use in relatively cramped quarters, and to permit the assembled unit to pass readily through doorways or narrow corridors, and between, around, or over ordinary pieces of furniture. When used by'maintenance men in ofiice buildings and the like, itican readily be moved from room .to room without dismantling: and carried from floor to floor on standard elevators. Because of thefactthat I'have providedv such readily manipulable means for assembling and disassembling the platform'frame and the end frames, the scaffold unit may be quickly and easily adjusted for various working heights, whereby the convenience and comfort and efficiency of workmen using the same are accommodated. Thus the high functional advantage of the structure illustrated herein over previously known scaffold units which require extended and tedious manipulation for adjustment or assembly and disassembly will be readily apparent.

I claim as my invention:

1. A scaffold unit comprising two ladders, each of said ladders comprising a pair of upright angle irons joined by a plurality of horizontally arranged spaced rungs, said uprights being arranged with one flange of each upright projecting toward the other upright and lying in a common plane with the corresponding flange of the mating upright, and with the other flange of each upright remote from, and parallel with the corresponding flange f the mating upright, said last-mentioned flanges being provided with a series of vertically-spaced perforations, two rails, each comprising an angle iron having a horizontal flange projecting horizontally toward the other rail and a vertical flange remote from the other rail, means at each end of each rail providing two vertically spaced elements selectively receivable in two perforations of a selected one of said uprights, to support said rails on said ladders and to connect said ladders together in spaced relationship, and means carried by one of said rails and readily connectible with, or detachable from, the other of said rails, to provide a bracing connection between said rails.

2. A scaffold unit comprising two ladders, each of said ladders comprising a pair of upright angle irons joined by a plurality of horizontally arranged spaced rungs, said uprights being arranged with one flange of each upright projecting toward the other upright and lying in a cornmon plane with the corresponding flange of the mating upright, and with the other flange of each upright remote from, and parallel with the corresponding flange of the mating upright, said last-mentioned flanges being provided with a series of vertically-spaced perforations, two rails, each comprising an angle iron having a horizontal flange projecting horizontally toward the other rail and a vertical flange remote from the other rail, means at each end of each rail providing two vertically spaced elements selectively receivable in two perforations of a selected one of said uprights, to support said rails on said ladders and to connect said ladders together in spaced relationship, and a platform supported on the horizontal flanges of said rails.

3. A scaffold unit comprising two ladders, each of said ladders comprising a pair of upright angle irons joined by a plurality of horizontally arranged spaced rungs, said uprights being arranged with one flange of each upright projecting toward the other upright and lying in a common plane with the corresponding flange of the mating upright, and with the other flange of each upright remote from, and parallel with the corresponding flange of the mating upright, said last-mentioned flanges being provided with a series of vertically-spaced perforations, two rails, each comprising an angle iron having a horizontal flange projecting horizontally toward the other rail and a vertical flange remote from the other rail, and means at each end of each rail providing two vertically spaced elements selectively receivable in two perforations of a selected one of said uprights, to support said rails on said ladders and to connect said ladders together in spaced relationship.

i. A scaffold unit comprising two ladders, each of said ladders comprising a pair of upright angle irons joined by a plurality of horizontally arranged spaced rungs, said uprights being arranged with one flange of ach upright projecting toward the other upright and lying in a common plane with the corresponding flange 0f the mating upright, and with the other flange of each upright remote from, and parallel with the corresponding flange of the mating upright, said lastmentioned flanges being provided with a series of vertically-spaced perforations, two rails, each comprising an angle iron having a horizontal flange projecting horizontally toward the other rail and a vertical flange remote from the other rail, means at each end of each rail providing two vertically spaced elements selectively receivable in two perforations of a selected one of said uprights, to support said rails on said ladders and to connect said ladders together in spaced relationship, a platform supported on the horizontal flanges of said rails, and means carried by one of said rails and readily connectible with, or detachable from, the other of said rails, to provide a bracing connection between said rails.

5. A scaffold unit comprising two ladders, each of said ladders comprising a pair of upright angle irons joined by a plurality of horizontally arranged spaced rungs, said upright being arranged with one flange of each upright projecting toward the other upright and lying in a common plane with the corresponding flange of the mating upright, and with the other flange of each upright remote from, and parallel with the corresponding flange of the mating upright, said last-mentioned flanges being provided with a series of vertically-spaced perforations, two rails, each comprising an angle iron having a horizontal flange projecting horizontally toward the other rail and a vertical flange remote from the other rail, a plate secured to the vertical flange of each rail adjacent each end thereof, and two vertically spaced pins carried by each of said plates and selectively receivable in a selected pair of perforations of one of said uprights to support said rails on said ladders and to connect said ladders together in spaced relation.

6. A scaffold unit comprising two ladders, each of said ladders comprising a pair of upright angle irons joined by a plurality of horizontally arranged spaced rungs, said uprights being arranged with one flange of each upright projecting toward the other upright and lying in a common plane with the corresponding flange of the mating upright, and with the other flange of each upright remote from, and parallel with the corresponding flange of the mating upright, said last-mentioned flanges being provided with a series of Vertically-spaced perforations, two rails, each comprising an angle iron having a horizontal flange projecting horizontally toward the other rail and a vertical flange remote from the other rail, a plate secured to the vertical flange of each rail adjacent each end thereof, two ver tically spaced pins carried by each of said plates and selectively received in a selected pair of perforations of one of said uprights to support said rails on said ladders and prevent relative movement between said rails and said ladders transaxially of said pins, and-means holding said rails and said ladders against relative movement axially of said pins.

'7. A scaffold unit comprising two ladders, each of said ladders comprising a pair of upright an gle irons joined by a pluralityof horizontally arranged spaced rungs, said uprights being arranged with one flange of each upright projecting toward the other upright and lying in a common plane with the corresponding flange of the mating upright, and with the other flange of each upright remote from and parallel with the corresponding flange of the mating upright, said last-mentioned flanges being provided with a series of vertically-spaced perforations, two rails, each comprising an angle iron having a horizontal flange projecting horizontally toward the other rail and a vertical flange remote from the other rail, 2. plate secured to the vertical flange of each rail adjacent each end thereof, two vertically spaced pins carried by each of said plates and selectively received in a selected pair of perforations of one of said uprights to support said rails on said ladders and prevent relative movement between said rails and said ladders transaxially of said pins, each of said pins being formed, in the portion thereof projected through the selected perforation, with a transaxial opening therethrough, and an element'positioned in said opening and cooperating with the associated upright to prevent relative movement between said rails and ladders axially of said pins.

8. A scaffold unit comprising two ladders, each of said ladders comprising a pair of upright angle irons joined by a plurality of horizontally arranged spaced rungs, said uprights being arranged with one flange of each upright projecting toward the other upright and lying in a common plane with the corresponding flange of the mating upright, and with th other flang of each upright remote from and parallel with the corresponding flange of the mating upright, said last-mentioned flanges being provided with a series of vertically-spaced perforations, two rails, each comprising an angle iron having a horizontal flange projecting horizontally toward the other rail and a vertical flange remote from the other rail, a plate secured to the vertical flange of each rail adjacent each end thereof, twovertically spaced pins carried by each of said plates and selectively received in a selected pair of perforations of one of said uprights to support said rails on said ladders and prevent relative movement between said rails and said ladders transaxially of said pins, each of said pin being formed, in the portion thereof projected through the selected perforation, with an axially elongated, transaxially extending slot, and a wedge element driven into each of said slots and engaging the associated upright to wedge said pin and upright against relative movement axially of said pin.

9. A scaffold unit comprising two ladders, each of said ladders comprising a pair of upright angle irons joined by a plurality of horizontally arranged spaced rungs, said uprights being arranged with one fiange of each upright projecting toward the other upright and lying in a common plane with the corresponding flange of the mating upright, and with the other flange of each upright remote from and parallel with the corresponding flange of the mating upright, said last-mentioned flanges being provided with a series of vertically-spaced perforations, two rails, each comprising an angle iron having a horizontal flange projecting horizontally toward the other rail and a vertical flange remote from the other rail, a plate secured to the vertical flange of each rail adjacent each end thereof, two vertically spaced pins carried by each of said plates and selectively received in a selected pair of perforations of one of said uprights to support said rails on said ladders and prevent relative movement between said rails and said ladders transaxially of said pins, each of said pins being formed with a transaxially extending groove in its lowermost peripheral surface designed and proportioned to receive snugl a portion of the peripheral wall of the selected perforation to hold said pin and upright against relative movement axially of said pin.

CARL C. DROEGER. 

